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This article presents results of experimental investigations of the durability of glass-fibre-reinforced polymer (GFRP) pultruded profiles exposed to typical environments of civil engineering applications. Specimens obtained from commercial GFRP profiles made of unsaturated polyester and vinylester resins were subjected to immersion in (i) demineralised water and (ii) salt water at 20 °C, 40 °C and 60 °C for up to 18 months, (iii) continuous condensation at 40 °C for up to 9 months and (iv) accelerated ageing in a QUV chamber for up to 3000 h. The effects of such exposure conditions on both types of profiles were analysed in what concerns their (i) mass changes, (ii) viscoelastic response, evaluated by means of dynamic mechanical analysis (DMA), (iii) mechanical response in tension, bending and interlaminar shear, and (iv) chemical changes, assessed through Fourier transformed infrared spectroscopy (FTIR). Hygrothermal ageing had significant influence on the material performance, namely on the mechanical response - demineralised water immersion caused a higher level of degradation, compared with salt water immersion, and results show a clear competition between moisture-induced plasticisation and residual post-curing of the composite matrix. Following QUV exposure, although considerable aesthetical changes were observed, the viscoelastic response and mechanical performance of both profiles were not remarkably affected, confirming that UV radiation affects essentially the outermost layers of GFRP profiles. In general, the GFRP profile made of vinylester resin exhibited better durability performance, when compared with its polyester counterpart. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify and characterize aetiological and predisposing factors in denture-related stomatitis (DRS), by means of a case–control, transversal study, in a large cohort of 140 persons wearing removable maxillary polymethylamethacrylate prostheses. Data were obtained by (1) a questionnaire that included the identification of the subject, demographic and social data, medical history and behaviour; (2) intra-oral examination; (3) evaluation of the prosthesis; (4) microbiological examination; (5) yeast identification and analyses using Epi-info and the chi-square test. Results showed significant associations between DRS and yeasts, gender, age and alcohol consumption. We also found a significant relationship between the presence of yeasts and hyposalivation and decreased salivary pH. We found a highly significant difference between groups with and without DRS concerning the presence or absence of yeasts, regardless of the sample origin. Most cases of DRS showed the presence of Candida albicans. The results confirm a highly significant difference between groups with and without DRS concerning the presence or absence of yeasts. [ABSTRACT FROM AUTHOR]

Paracoccidioidomycosis (South American blastomycosis) is a systemic mycosis which can be associated with oral lesions. This study on a group of 14 patients showed oral lesions mainly on the gingival or alveolar mucosa, with pulmonary involvement detectable on chest radiography in most. Microscopic detection of the fungus on a direct smear showed positive results in all 14 patients. Serological investigations including immunodiffusion, counterimmunoelectrophoresis and immnunoblot were also positive in 100% of cases. The results suggest that direct smear together with serology may obviate the need for lesional biopsy for the diagnosis of oral paracoccidioidomycosis. [ABSTRACT FROM AUTHOR]